Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!kddlab!titcca!cc.titech.ac.jp!necom830!mohta
From: mohta@necom830.cc.titech.ac.jp (Masataka Ohta)
Newsgroups: comp.arch
Subject: Re: vfork (was Re: Paging page tables)
Message-ID: <5876@titcce.cc.titech.ac.jp>
Date: 17 Jul 90 02:19:29 GMT
References: <920@dgis.dtic.dla.mil> <5830@titcce.cc.titech.ac.jp> <5DL4SPD@xds13.ferranti.com> <5855@titcce.cc.titech.ac.jp> <180@array.UUCP>
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Organization: Tokyo Institute of Technology
Lines: 31

In article <180@array.UUCP> colin@array.UUCP (Colin Plumb) writes:

>I'd just like to point out that Unix can already run out of swap space
>at invconvenient times.

Yes. I have already pointed out that in

	Message-ID: <5844@titcce.cc.titech.ac.jp>
	Date: 12 Jul 90 04:15:11 GMT

	:With vfork, such a situation never occur (except for stack segment),
						   ^^^^^^^^^^^^^^^^^^^^^^^^

and in the previous discussion on the same vfork topic about half a
year ago.

>Should blow up on anything that dynamically grows the stack.  So by allowing
>a process to die if it hits a bad COW case we aren't breaking the semantics
>too badly,

As I said about half a year ago, growing stack problem is not so
serious, because most programs (espacially, important system processes)
can do with the initially allocated stack segment and it is much less
likely to occur.

>although obviously the situation should be avoided if at all
>possible.

So, it is important to reduce the possibility.

						Masataka Ohta